Tom de Vries <tom_devr...@mentor.com> writes: > On 16/04/14 12:28, Richard Sandiford wrote: >>> > This patch introduces a hook that specifies which registers are >>> > implicitly >>> > clobbered by a call, not including the registers that are clobbered in >>> > the >>> > called function, and then uses that hook to add those registers to >>> > CALL_INSN_FUNCTION_USAGE. > >> I don't think a new hook is needed. > > Richard, > > the hook enables us to determine whether a target supplies the information > provided by the hook. If the target does not provide this information, the > fuse-caller-save optimization is possibly not safe. > > How do you propose to handle this without this hook?
Maybe we should just have a bool field in the target structure to say whether -fuse-caller-save is supported, a bit like delay_sched2. Thanks, Richard
